Project Summary The proposed project is designed to identify alterable factors in the food and physical activity (PA) environment that contribute to declines in obesity rates among school children. Childhood obesity has been associated with higher risk for cardiovascular disease both during childhood and later as adults. While overall obesity rates remain high in the US, there have been promising reports of declines among specific subgroups across the country. Yet, little is known about the causes of such declines. This project aims to identify changes in the food and PA environments in schools and the surrounding communities that predict sustained obesity declines over time among a panel of K-12 schools, and explore whether these predictors differ by race/ethnicity, age, and gender of students. The project will also identify those community- and school-level changes that are most common among schools with sustained obesity declines and examine whether the distinguishing changes differ by race/ethnicity, age, and gender. The study will prospectively follow 120 schools (30,000 students/year) over the eight-year study period. Building on our pilot data and established rapport with school nurses, professionally measured heights, weights, and demographic data on students will be collected at four time points. At parallel times, school nurses will be surveyed to identify changes in food and PA environments in the schools (e.g., salad bars, drinking water in cafeterias, recess) and changes in the food and PA environment surrounding schools will be documented (e.g., new / renovated parks and trails and upgraded corner stores). Changes will be geocoded to establish proximity to schools. The Impact of our proposed research derives from our having identified schools for study that have experienced declines and increases in obesity rates and our ability to identify alterable factors in the environment that can be linked to obesity trends among varied age, gender, and race/ethnicity groups. The findings will provide critical evidence for developing tailored community and school interventions for reducing the burden of childhood obesity.